Behavioral and Physiological Metrics

This Chapter 7. of Tullis and Albert, Measuring the user experience, it worth reading although it will not easy to apply in UX tests. A list of the metrics:

1. Just observing and coding behaviors taking notes in a form or in a open format, verbal and non-verbal ones (see form on page 170)
1.1. Verbal comments: positive/negative comments, doubts, questions...
1.2. Non-verbal behaviors to analyze: facial expressions and body language

2. Using specific devices
2.1. Facial expressions
- Video recording analysis (time consuming), and classify them, ex. FACSAID 2002
- Electromyogram sensors (EMG), specially for forehead and cheeks
2.2. Body language to measure stress-frustration and engagement
- Mouse gripping
- Chair pressure
- Skin conductance
- Heart rate
- Pupil dilation
2.3. Eye tracking
- Proportion of users looking at a specific element or region (AOI*)
- Time spent looking at a specific element or region (AOI)
- Time to notice a specific element or region
- Scan-paths and length of eye movements

*Tips about AOIs:
- do not leave any space undefined
- analyze the time as a percentage of total time spent on the page, not as an absolute amount of time, since it can vary widely between participants